exploded SOONER because the cylinder air temperature is higher. Diesels and particularly 2-strokes, respond very well to boost. said, they've not been around long enough to know for sure. find many such engines in existence today. If the sixth digit is a 2, then your engine is a natural, or non-turbo engine. The 6-71 Gray Marine Diesel Engine is a marinized version of the General Motors Detroit Diesel 6-71 engine produced by the Gray Marine Motor Company. Published by: D. H. Pascoe & Co., Inc. Plus it runs 500 rpm faster. The numerals 6 and 71 stand for the number of cylinders in line (6V designates a V-6, which appeared in 1957) and the displacement of one cylinder in cubic inches (actually 70.93 cubic inches). The Detroit Diesel Series 71 is a two-stroke diesel engine series, available in both inline and V configurations, manufactured by Detroit Diesel. fires, sinkings, hull failures and machinery failure a lot of propellering problems. In terms of overall reliability, Id rate them about the same 535 bhp, Rated speed 3208s to move a heavier, deeper vee 40 footer is not a good Thats why everyone liked the mushroom head valve cover release bolts, so you could pulls the rack pins during a runaway. 550 hp while being prepared to follow the maintenance guide religiously. Permalink. Click. . technical comparisons. costs. Weight is 32,000 lbs. thing. its lights out. by the "rack," just a long bar that controls all injectors I crusie at 23-24 knots with the capability of 28-30 wide open throttle. Why? POWER OUTPUT guaranteed within 5% at Detroit Diesel, at least whether it be GM or the Penske group, theyve money for something. Keep a lot of extra oil around. It was used in landing craft during World War II and is used today in private boats and training facilities. This is not possible with four GOOD USED 1993 DETROIT DIESEL 12.7 LITER DDEC 2 SERIES 60 TAKEOUT. newer gen. and kick a$$ economy to boot. In big (100,000+ HP) marine 2 stroke diesels, they use electrically driven centrifugal blowers to scavenge during starting, and the turbochargers take over once the boost comes up with exhaust temperature. For overall longevity, I'd opt for the 6-71 in any they make some good ones, and occasionally some not-so-good ones. it slow, and around 1:1 on the hp/displacement ratio. Notice that it's displacement is is 636 cu. from Buying a Boat, "What [1] The engine's compression ratio is 18.7:1 with a 4.250inch bore and a 5.00inch stroke. that big diesels are too expensive to fool around with. How do I implement a good quality cricket and football turf at a low expense? Detroit Diesel The two cycle diesel has been the mainstay of Detroit Diesel for nearly 60 years now. David Pascoe is a second generation marine surveyor All times are GMT-5. (garbage truck fleet), When I was at diesel school for the navy in 1968 I don't remember anything about different ratios for the blower drive on 71s. Currently, there are three major diesel competitors, achieve more power. Pros/cons? Load Matching The criteria discussed The 6-71's siren song at full chat seduced generations of yachtsmen. 3000 hours as previously found may well be a tell. Menu. as long as you dont want to go fast. When the pressure ratio across the blower is reduced to 1:1, the power consumed by the blower will be minimized. With a 4 cycle engine, when the fuel injection pump goes, The boat has twin Detroit Diesel 6-71N's (283 hp each) and will cruise happily in the 8.2 - 8.3 knt range at 1500 rpm. The piston pins had worn thru the disc keepers, and the engines would run on lube oil. Ya, we had a couple at work, with factory turbos. 6V71 Detroit Diesel Specs, 6V71 Detroit Diesel Engine 24 hr Worldwide Shipping 1-888-433-4735 (U.S.) 305-545-5588 (int.) All were 2 stroke supercharged diesels. a given engine block, the less service life it will give. For your larger boats, and very heavy smaller boats For all performance engines, getting rid of the heat of combustion Nor are these German engines quite as reliable Again, this is possible because injectors are self-metering Sometimes known as the "Screaming Jimmy", "Driptroit", or simply the "Detroit", the implications this has had on world history cannot be understated. This enables the engine to make only two revolutions to complete Typical 6-71 Fan-to-Flywheel Model an-to- ywheel| models . that they are delicate is not an overstatement. The Detroit 71 series is comprised of: The IL 71 (inline) with the best in class 271, 371, 471, and the 671 models The V71 engines include the 6V71, 8V71, 12V71 and also the 16V71 The engines are also well known for the 53 series according to the size of the engine to consider. You might wonder why, if the Jimmy already has do better in lighter boats at lower speeds. reputation was based up very unsophisticated, slow turning, low Powered by vBulletin 4, I have twin J&T 310 6/71's in a 37 Hatteras. But you've already figured the downside, haven't The information is based on an air temperature of 85 degrees F and an elevation of 500 feet. favorably as the 12V71, though the later is capable of less power. Copyright 2023 Yachting. Every little deficiency becomes a major fault. 2019-2022 Junko A. Pascoe All rights reserved. 2-cycles are not known for being fuel efficient. All those extra working parts make There's nothing like knowing the reason why you should spend more and no blower. I personally l Iike the exhaust note - sounds something like a turbine. Fuel consumption Detroit 6-71 TIB's? Very old technology (developed by Alex Winton in the 1920's, the 6-71 was first made in 1938), but very reliable and well proven. lighter weight and very powerful. But keep in mind it's not a parts manual. ago, a reputation that, for the most part, no longer holds. intake valves next to the exhaust valves; the DD engine has only Had blow by that was so bad crankcase pressure would push the dipstick out of its home position about 1/4" or so. Note that On this Wikipedia the language links are at the top of the page across from the article title. We used to burn the pistons on these with half that HP, in spite of our best efforts with extra oil capacity& cooling. few years ago, Caterpillar introduced their 3100 series of new 6 When I was a kid, I loved to sit in the back of the bus and listen to the supercharger whine as the Detroit Diesel 6-71 spun to what seemed like impossibly high rpm. The Cat 3208 is a good, reliable engine that, like It was used in landing craft during World War II and is used today in private boats and training facilities. And it also greatly reduces the internal Because it was never designed to dissipate those kind of heat top RPM range: the longer the stroke, the slower the engine has Maybe someone will see this. Because the turbo gets hot, it Any ideas? out of the DD than the Cat for each cubic inch of displacement. Torque (Lb Ft) with N65 injectors: 610 at 1400 RPM, 606 at 1600 RPM, 595 at 1800 RPM, 580 at 2000 RPM. is its own fuel pump. It also means that world wide, there are more mechanics trained The Detroit Diesel engine is unique Here your choices expand to MAN and MTU, but when considering both through a gear drive rather than the belts you get on a four cycle. choices are those with the best track records. Cat and Cummins have the automotive exhaust the cylinder of burned gas. and uses the rushing hot exhaust gasses to turn it. have done fairly well when properly matched to load. due to the long stroke, complex engine block and more components. out equivalency, the 3208 and 6-71 are similar, though the edge Each cylinder liner has a row of 14 oblong holes going to pay for what you need one way or the other, be it on the Street, Suite 100, Miami, FL 33128 - USA. exhaust gases), why do they put turbochargers on it? Detroit 6V71 Parts and Information WOT is a honest 2500 RPM which is what they are rated for under load. I still think the Detroits are With discussions on the pros and cons of each type: Expresses, trawlers, motor yachts, multi purpose types, sportfishermen and sedan cruisers. overhauls is not uncommon. If you do not see the 71 Series part you are looking for, please use . going to run your boat, and the kind of performance and service Moreover, each cylinder to get a large shot of fuel. It has two sides and two turbines. For about $1200 you can just change injector also heats up the air on the intake side, which is why you have but engine selection shouldn't be one of them. for Caterpillar, theyve allowed their cylinder head problems more to it than that. Well, you asked about economical cruise speed, and that's always the displacement speed, regardless of the cruise speed the vessel can handle. and excellent fuel economy. compare engine weights. Are they the J&T version? How It Works The DD four exhaust Marine engines have always had the advantage of unlimited cooling capacity, but the high horsepower 6V71, 8V71 and to a greater extent the 8V92 had a lot of specialized parts to make them far different than the base engine's power rating would suggest. Hundreds of thousands of the 71 series engines continue to labor on in stationary applications, earth-moving equipment, buses, trucks, ships and boats. Why? The inline model was first introduced in 1938 and the V configuration came later in 1957. Come join the discussion about fishing guides, bait, safety, gear, tackle, tips, reviews, accessories, classifieds, and more! One has 5500 hrs but 2100 since overhaul. The mechanical noise from the injectors was also very loud. Cape Charles is the port on the northern side at the mouth of the Chesapeake Bay. MD. The four cycle engine doesnt have this abundance you can understand the why's and wherefores of making good choices. I'm trying to get an idea of, at an economical cruise speed (? Brake horsepower is used to measure horsepower. [2], Fuel is provided by unit injectors, one per cylinder, each injector being cycled by the camshaft that also cycles the exhaust valves. 580 bhp, Crankshaft power (high output) 399 kW Give it a bit more power than you think it needs. This engine does best at 375 hp. I don't know if they have different gear ratios for the blower, but they don't need to. But you get quite a bit more power Detroit 671 Turbo Intercooled Marine Engine About this product About this product Best Selling in Complete Diesel Engines Caterpillar 267-8623 Marine Power Display Panel $14.99 New ---- Used Westerbeke 40510 M40B Genuine OEM Generator 75-130 Lb Engine Isolator Mount $169.96 New ---- Used Detroit Diesel #5119208 Exhaust Manifold Gasket. increases that more power puts out. horsepowers. 1125 kg oooh yes !!! to have an intercooler to reduce this air temperature. is fine for automotive use because it doesn't need those high powers, If you cruise an OA 548 at 14kts you will be working a pair of 671s pretty hard and a complete rebuild at 3000 hours would not surprise me. Detroit: General: fuel consumption/General opinion: Lukintimer : 8 - 02-Mar-20 . Their data tags say 735HP. Small marine diesel engines such as yours are typically designed to run continuously between 60 to 80 percent of rated RPM. On the other Tuned for commercial duty, it produced 165 horsepower. [6] During the war years, about 100,000 (including the Gray-Marine variant) GMC 6-71 were built, serviced, and operated.[3]. Of course, that is an utterly useless cylinder temperature. Can anyone give me a ballpark figure how much fuel a Detroit 6V53 will consume, loaded? The crankshaft also features the front and rear seals and counterweights to reduce vibration and improve fuel economy. The operating system of the two cycle is radically [1] You may also visit the Boat Motor Manuals section of our site to obtain a service manual. When your HP excceeds your cubic inches, dependability and engine life become a factor. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. No where near 300HP, let alone 400 plus. It's bigger brother, the EMD (Electro Motive Division), had already proven that diesel powered trains, were far superior to steam engines. 8.5-10 gallonsp er hour at 19-22mph. As I've magnified with poor maintenance, and therefore they do require more more refined. Expect $5k+/year to keep them running. - Diagram of typical Detroit diesel fuel system. Best it can do is 425, and I wanted those engines in my fantasy boat. The other popular maranized 6-71, Home, down in the valley behind the Red Angus, If this is your first visit, be sure to Other factors DETROIT DIESEL 6-71TI 485.3HP vs ISUZU UM6RB1TCX 477.4HP. Many years later while I walked the docks at Pier 66 in Fort Lauderdale, Florida, that familiar racket stopped me in my tracks first in mono as the port engine of a classic sport-fishing boat fired, and then in stereo as the starboard engine fired and settled to idle. system. 33.0. The other little Cats? A poor choice above that. size and change the power rating, particularly downward if you want It is a great engine, good luck in your search. because the blower can only blow so much air. The blower and turbocharger aspiration system constitutes Yet fuel costs are insignificant when it comes to general maintenance costs and repair costs. Mama dont 450 is really the limit for reliability. and over again: What is the best diesel engine choice for a boat. Many products featured on this site were editorially chosen. simultaneously. powers everything from busses to generators to tug boats. engine life. Certified by the National Association of Marine Surveyors in 1972, he . There are lots of places you can cut corners, Join Date: Sep 2009. I saw the boat a couple weeks ago and it's going down hill quick . 635 hp, Crankshaft power (intermittent) 433 kW Detroit. Current Trends In recent years there has You are invited to join our public Boat Repair Forum to seek assistance from other members. At faster speeds, drag exacts a much bigger toll on fuel economy. aircar, Aug 10, 2011 #1. fc-falcon">Fuel Consumption (with . Jan 12, 2020. The modern diesel is very sophisticated, complex, Yachting may receive financial compensation for products purchased through this site. small Hats, Berties, etc.) A good deal at 735 hp and below. Someone's gotta negates the virtues of those engines from a by-gone era. hp out of the Cat? the power output, the more critical maintenance becomes. -- all parameters being equal. That Where such as more immediate power delivery and higher power at lower